These three quasars, recently discovered at optical
wavelengths by the Sloan Digital Sky Survey, are 13
billion light years from Earth, making them the most
distant known quasars. The X-rays Chandra detected were
emitted when the universe was only a billion years old,
about 7 percent of the present age of the
universe.

A surprising result was that the power output and
other properties of these quasars are similar to less
distant quasars. This indicates that the conditions
around these quasars' central supermassive black holes
must also be similar, contrary to some theoretical
expectations. As astronomer Smita Mathur of Ohio State,
who was involved in the research said, "Perhaps the most remarkable thing about them is that they are so absolutely unremarkable."

By various estimates, the supermassive black holes in
these quasars weighed in at somewhere between one and
10 billion times the mass of the Sun. The implication
is that the black holes put on a lot of weight soon
after the galaxies formed.